The present invention relates generally to the transporting of disabled persons, and, more particularly, to an improved carriage or harness for attachment to a disabled person to be transported by a hoist.
Transfer hoists for disabled persons are typically used by paraplegic, quadriplegic, handicapped, weak, or elderly persons for transport from one place to another, such as from a wheelchair to a bed, etc. Such hoists are well known in the art, and examples can be seen in the following U.S. patents: U.S. Pat. No. 4,944,056 (Schroeder et al.); U.S. Pat. No. 4,125,908 (Vail et al.); U.S. Pat. No. 3,677,424 (Anderson); and U.S. Pat. No. 2,650,725 (Hoyer et al.).
A critical element of every hoist system is the carriage or harness which is attached to the patient and also connected to the hoist. Despite the many advances made in hoist systems in general, including the many safety features as found, for example, in the Schroeder patent recited above, problems still exist in the art with respect to the carriage.
Ideally, the carriage should, above all, be safe. The patient must be prevented from falling out of the harness at all times during transport, including lifting, moving laterally, and descending. The carriage should have ample headroom, so that the patient cannot bump his head during transport. Also, the carriage should, as much as possible, distribute the lifting forces about the body, since excessive pressure in any one area can be uncomfortable if not injurious.
The ideal harness should be comfortable for the patient. In this respect, elements of the harness which are in contact with the body should be cushioned or padded. The harness should also be lightweight and inexpensive. It should also be of an extremely stable design, which is a real engineering challenge when one considers that the disabled person is suspended in air and is usually unable to assist in stabilizing himself.
Most early hoists used slings or straps to support the patient (e.g., Hoyer et al., supra). Straps, used alone, to support the legs and thorax of a patient can be extremely uncomfortable and even injurious. Straps can cause cutting or chaffing of a patient's skin, and, as demonstrated in FIG. 2 of U.S. Pat. No. 2,650,725, can place undue pressure on a patient's back. A further problem with the device disclosed in the above-recited patent to Hoyer et al. is that the patient can actually slip out of the harness between the thoracic and leg slings.
Further examples of sling designs can be found in U.S. Pat. No. 3,677,424 (Anderson) and U.S. Pat. No. 4,944,056 (Schroeder et al.).
An improvement over the sling design is disclosed in U.S. Pat. No. 4,509,785 (Van Raemdonck et al.) and an associated product manufactured by Handi-Move of Belgium. The Handi-Move device uses a "scissor-arm" frame design with extensions which support the patient under his arms. The device does not use any slings, but does use leg supports which slide under the thigh to create and support a sitting position. A problem with the Handi-Move design is that it creates excessive pressure under the patient's arms, and does not distribute the forces associated with lifting. A second problem is that, when the patient is lowered, and as the legs come in contact with a bed or other surface, the leg supports tend to become disengaged which de-stabilizes the device, which can allow the patient to fall out of the back of the apparatus.
Thus, there is a need for an improved carriage or harness for transporting a disabled person which distributes the forces associated with lifting over a greater surface area of the person and does not exert most of the force under the person's arms, thereby making the device more comfortable to use, and which also includes leg supports which do not easily disengage when the person is lowered into contact with a bed or other surface.